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Live forecasts update automatically; written guidance last reviewed 23 June 2026 by the Southern Pulse Weather Desk. Data from the Bureau of Meteorology (BOM) and other national met services via Open-Meteo.
Live data from Open-Meteo · updates automatically ·
A bomb cyclone is a non-tropical low-pressure system that undergoes explosive deepening — a pressure drop of at least 24 hectopascals in 24 hours. For New South Wales, this typically brings damaging winds, heavy rain and coastal erosion, most often during the cooler months when the temperature contrast across the Tasman Sea is strongest.
What exactly qualifies as a bomb cyclone?
The term “bomb cyclone” is short for explosive cyclogenesis. Meteorologists apply it when the central pressure of a mid-latitude low falls by 24 hPa or more in a day. The faster the pressure drop, the more intense the winds and rainfall become. In NSW waters, the phenomenon is most common from late autumn to early spring, when cold air from the Southern Ocean collides with warmer sea-surface temperatures.
How does a bomb cyclone affect NSW weather?
The NSW coast bears the brunt because the system deepens rapidly as it tracks east of the Great Dividing Range. Damaging wind gusts (often above 90 km/h) can topple trees and bring down powerlines. Heavy, persistent rain may cause flash flooding in urban areas, and large swell combined with king tides can erode beaches and threaten coastal properties. The live ranking above shows current severe-weather warnings for affected centres.
Is a bomb cyclone the same as a tropical cyclone?
No. A bomb cyclone is a mid-latitude (extratropical) system powered by strong temperature gradients, not warm ocean waters. It can still cause similar storm-force winds and heavy rain, but it forms in cooler latitudes.
Should I prepare differently for a bomb cyclone than for a normal storm?
The main difference is the speed of intensification. Check live severe-weather warnings and secure loose outdoor items early, because winds can ramp up quickly. Follow advice from local emergency services and the Bureau of Meteorology.
How often do bomb cyclones hit NSW?
Roughly one to three significant bomb cyclones affect the NSW coast each year, though weaker systems occur more frequently. Recent climate modelling shows no clear trend in frequency, but individual events may become more intense as sea-surface temperatures warm.
Sources
For the latest information on storms and watches, see the Australia weather hub or the live weather radar.